Reinforced concrete construction of ships, floating docks, pontoons, and the like



H. C. RITC HIE AND M. KAHN. "REINFORCED CONCRETE cowsmucnom 0F SH-IPS, FLOATI'NG DOCKS, PONTOONS, AND THE LIKE.

. APPLICATION FILED AUG-7,19I8.

Patented Apr. 19, 1921'.

8 SHEE]S-S'HEET I.

Mar: i232 Kw/an H. C. RITCHIE AND M. KAHN. REINFORCED CONCRETE CONSTRUCTION OF SHIPS, FLOATING DOCKS, PONTOONS,

ND THE LIKE. Patented Apr. 19,- 1921,

APPLICATION FILED AUG. 7, 1918- H. c. RITCHIE AND M. KAHN. REINFORCED CONCRETE CONSTRUCTION'OF SHIPS, FLOATING DOCKS PONTOONS, AND THE LiKE.

APPLICATION FILED AUG. 7, 1918- 1,3?5,179@, Patented Apr. 19,1921,

8 SHEETS-SHEETS- In uenfai-si J'iarz y C. Rife/2:19,?

nziz 1K ahn,

H. C. RITCHIE ANDIVI. KAHN.

REINFORCED-CONCRETE CONSTRUCTION OF SHIPS, FLOATING DOCKS, PONTOONS, AND THE LIKE.

APPLICATION FILED AUG-7,1918- l,3'?5,179. Patented Apr; 19, 1921.

8 SHEETS-SHEET 4-.

a g In mentor Jiarry C. R iichl'e a mMoG/m H.' C. RITCHIE ANDM. KAHN. UCTION 0F SHIPS, FLOATING DOCKS, PONTOONS, AND THE LIKE.

I APPLICATION FILED AUG- 7, 1918. 1,375,179. Patented Apr. 19, 1921.

-8 SHEETS-SHEET 5.

REINFORCED CONCRETE CONSTR Irazentors:

(Harry C.fiz'tchie,

(7 70 f2 Jfah @V% m maid M H. CIRITCHIE AND M. KAHN. REINFORCED CONCRETE CONSTRUCTION OF SHIPS, FLOATING DOCKS, PONTOONS, AND THE LIKE.

APPLICATION FILED AUG.7, 1918- Patented Apr. 19, 1921.

8 SHEETS-SHEET 6- Invent-01w: Jfozrzzy C. Rl'?;072

wonz'fz .Kah oax/ 64 .llIlhll I H l l I H H HHH IWHH H HH II l l l I HI IHI I I I Hl l l H. c. RITCHIE'AND M. KAHN.

' REINFORCED CONCRETE CONSTRUCTION OF SHIPS, FLOATING DOCKS, PONTOONS, AND THE LIKE.

.APPLICATION FILED AUGJ, I918.

' Patented Apr. 19, 1921 8 SHEETS-SHEET 7.

flaventozw? in h 0.42M MGMQI;

Jiwrry 0., fijtekiea H. 0. RITCHIE AND M. K-AHN. REINFORCED CONCRETE, CONSTRUCTION OF SHIPS, FLOATING DOCKS, PONTOONS, AND THE LIKE.

, APPLICATION FILED AUGJ, I918. 1 75,179, Patented Apr. 19, 1921.

ex; 0172;,- At y? B SHEETS-SHEET 8.

UNITED srA'rss 'HARRY 'C.'RITCHIE, QF=LIVEBPOQL AND 'MORITZ KAHN, OFLONDON, ENGLAND.

PATENT OFFICE;

REINFORCED conc E'rE:consfisaucmronorsnrrs,:ELQATING nooKszjronroons AND THE LIKE.

I Application ,fi le d August '7.

To; all whom'z't concern: a p

Be it'known hat we, HA RY CLEM NT Rl 'rornn, ,a subject ef the King of Great Britaim an'd ;residing in Liverpoohjin the unty of La caster, Engla d; a B T Kar n, a citizen of theUnited States, and residing in London, England, have invented certain new ,and useful Improvements in Reinforced Concrete Construction of Ships,

Floating Docks, iPontoo,ns,,,and the like, of

nessof plating and scantlings. Furthenbbjects, such as,,elimination,of difliculties due to shrinkage, increased facilities. for repair work and greater freedom to the designer in the newshipbnilding material, will transpire as the invention and the ,modeof-carrying itintooperationare disclosed in what 7 follows.

To those experienced'in the behaviorqof concrete as ,a structural ,material, ,it is" well known that it is practically .impossibleto construct thin slabs of any considerable length which willnot crack on maturing;

further that the positions where cracking will take place cannot be determined beforehand, because many varying factors affectthe conditions resultingin the cracks, e. g. the positions of breaking off and jointing during construction, lack of .uniform quality of concrete, varying thickness,

varying atmospheric conditions during construction, and so on, as well as the posi tlons of reverse bending. The construct on of aconcrete boat,,even of relatively short length, with a .thin shell in the ordinary monolithic manner would for these reasons be attended with considerable difficulties;

. cracks and leaks would inevitably follow and efficient repair would be exceedingly difficult. It has been proposed to protect a steel ship with an outer protective skin formed of multiple layers of pro-cast reinforced concrete flanged slabs whichare subsequently assembled with the flanges abutting, the vjoints between the flanges being made water-tight by. cement keys and in other ways, and it has been proposed that an entire ship could be constructed of slabs shaped assembled in multiple layers and jointed, as above described; the stressesto p cation of Lett r -Pa en ammed A r; 19, 1921.

e s. Serial No, alarm;

which a shipishullare subjected are howeversuch as can only be provided for in ships of even moderate size suitably .idis

posed continuous main frame members and the present invention differs from the suggested arrangement for building entire ships of slabs 1n, the manner described, inasmuch as according to the present invention the reinforced concrete ship is built up of units separately molded and matured and of suitable frame members'cast in situ; the unit sectionsare of suchshape as to be adapted to be readilyjointed together and the general design issuch that the main through members can be cast in sz'tu about the said sectionsas the latter are assembled and such that a continuous system of cross bracing and auxiliary through members can be ap- I pliedito provide for the usual stresses met with in i such structures.

One set of'main frame m'e nbers,-saygthe transverse frame members are preferably pr e-molded integral with the shell units, 1

the said .members being connected together through or within the fiframe members cast in situ, in which case such units correspond" in shape withunits whieh would be obtained if a steelhull were dividedfby aseries'of transverse planes passing through the cente of h fram g'aad y a s rieso p ane normal to the shell and passing through the main longitudinal rnembers of the ship.

vSuch units, therefore'have a width equalto the.lgngitudinalspacing of the transverse frames,asdeterminedfby Lloy ds rules, and,

1 eng hIeeua to t transv s Spac n Of the ma n longitud nal members. Each unit thuscomprises a slab provided withflanges,

the slabcorresponding with the plating and theflanges withthe transverse frames, said flanges forming jointing surfaces of considerableextent, the two connected flanges o djacent slabs thus farm ng t e on frame. tend vertically from the, sheer strake to the next side stringer and so on; suitably curved units extending from the stringer at ,the junction of ,side framesiand bilge frames to the bil lgeelson, and horizontally arranged units extend from the bilge keelson to the middle keelson, the flanges of the .units in thelatter case forming the floor plates, or transverse beams in the construction of thebottom.

The transverse deckimelnbers with suit One tier ofsuch units would ex tudinal members so as to form a single inte-' gral reinforced structure.

In order to reduce the thickness of the slabsto a minimum, the slabs are reinforced in both directions and are for thispurpose divided in squares, stirrups beingleft protruding from the inside faces to take secondary beams.

Openings are provided in the sides or flanges of the units through which pass the main reinforcing bars of the secondary beams, which bars are anchored to the slabs and run continuously across the abutting faces of the units. These reinforcing bars may in some cases run diagonally through the openings, the ends of the bars being anchored at intervals into the main longitudinal concrete members which are cast in situ.

This diagonal arrangement has great advantages as an efficient means of resisting not only the shearing forces in the sides of the ship acting as the web of a deep girder, but also in the resistance of racking or torsional stresses across the whole transverse section of the ship.

The unit sections can be cast in a horizontal position on the ground or on benches, and owing to their small size could be much more efliciently supervised during construction than would be possible otherwise. Also they could be tested individually after maturing and before being incorporated in the ship structure.

In the present proposed system of construction, the transverse unit has been adopted because the transverse structural strength. of a ship is less variable than the fications.

The invention'is illustrated in the accompanying drawings which show the application of'the invention to a ship of moderate size.

In the drawings, Figure 1 is a perspective view of one of the unit sections extending from the sheer strake to the next lower main stringer, portions of the two adjacent sections being shown to indicate the mode of jointin and portions of the longitudinal members eing shown to indicate the mode of attachment and the mode of diagonal bracing; Fig. 2 is a perspective View of a unit section suitable for floor plates and bottom shell plating.

Fig. 3 is a half mid-ship section showing the several kinds of sectional units joined together by the longitudinal members.

Fig. 4: is an elevation in section on the line IV, IV of Fig. 3; Fig. 5 is a similar view but shows the method of diagonal reinforcement; Fig. 6 is a fragmentary view of a part of Fig. 5 but to ajlarger scale, and Fig. 7 is a fragmentary horizontal section to still larger scale, showing tWO frames and the intervening shell plate.

Fig. 8 is a plan view in section on the line VIII, VIII of Fig. 3; F ig. 9 is a similar view but shows the method of diagonal reinforcement, and Fig. 10 is a fragmentary plan view showing the mode of attachment to the center keelson.

Fig. 11 is a transverse section through the Fig. 14 is a similar View of the bilge keelson and Fig. 15 a similar view of the center keelson.

Fig. 16 is a transverse section through a deck beam unit and shows the detail of the hatch coaming, and Fig. 17 is a sectional elevation of the hatch way and coaming.

Referring in the first instance to Fig. 12- The unit section A is adapted to extendvfrom the sheer-strake B to the'next side stringer C. 05 is skin or shell plating, a the flanges or sides, adjacent pairs of which form the transverse frames. a are the horizontal and a the vertical reinforcing bars of the shell; the horizontal bars a are anchored in the flanges a forming therein shear resisting stirrups, and the vertical bars a may protrude at their upper. ends and be anchored into the sheer strake.

. a are the main reinforcement bars of the flanges or sides a at their upper ends they are hooked around the main reinforcement bars 6 of the sheer strakev and at their lower end they pass around the lowermost of the holes a and in. this way,areunited to the main reinforcement bars 0 of the side stringer C.

.The upper ends of the flanges or sides a are widened to suppcrtthe knees 'D of the deck beams D (shown in dotted lines in Fig. 1), and the ends of these beams are transversely indented as shown, so as to make effective joint with the sheer strake When the latter is molded in position.

The joints between .adjacent sides or flanges of the unit are madeby bringing :the 'faces of these-flanges intoalinement .(as shown inig. 1-), a minimum space-being left between. the faces, which spaces are afterward run in with agrouting of cement 'orthe like Y Holes a which come into .alinementare provided in'the flanges, and through these holes areIthreaded-Jeither ilongitudinal bars a as shown, for-example, on the left :hand side'of Fig/4c, or diagonal :bars 0. as shown in Figs. 1 and 5; orof course both diagonal and longitudinal bars .maycbe fitted.

Projecting :stirrups' 'such as f6", shown in Fig. 2, may :protrude'from .the. slab so that the bracing bars run between the sti'rrups which are iturned over as show 111v g- 2, and in this 'way securely anchorithe reinforcement bars to theslab.

The upper ends of the reinforcement bars a are hooked into the sheer'strake asshown in Fig.- 1,:and the lower endslareihooked into the next main longitudinallbelow the sheer strake-in this case thee-side stringer C; this stringer,.after the side 'row-of units Aand the bilge units F (-See'EigLB) have beenassembled, is formedby running the main reinforcement bars '0 of- .the side stringer through the holes a and f, which bars are supplemented by further bars as shown inthe detail ofthis stringer in Fig. 13, the bars being united bystrap links 0 and stirrups 0 after whichthis stringer is V molded in situ and forms a horizontal member uniting the horizontal abutting surfaces of the units A and F.

Projecting stirrups a are'fittedto the inner edges of the flanges of the units and are adapted to form attachments for the inner .lining K where one is fitted This lining may be of cement, plaster or any other suitable fibrous composition, wood or the like.

Additional and outer holes a may bev formed in the flanges to take additional longitudinal bars such as a which may beling shown by dotted lines. 6 is the shell plating or skin; 6 the flanges or'sides which form the floor plates; a and e are, respectively, the fore and aft and transverse shell reinforcement bars; e are the main reinforcement bars, and. they protrude and are turned over and are anchored atthe central part into the main bars 9 of the center keelson'G as shown in FigsqlO and 15, and at the other end are anchored into the main reinforcement bars 7L ofthe bilge keelson H,

asshown in'Fig. '14 the transverse bars 6 -of:;the shellplating also project and are anchored into the center .keelson at the one :endand intothebilge keelson at the opposite end. iTlie-endsiof'the flanges or floor plates are indented :ZLS'ShOWIl so as to forma key at the one end with the center keelson and at the .othenendwith the .bilge .keelson. e .are'the holes in .the 'YflOOI plates, through which longitudinal bracing bars 6 ondiagonal bracing bars 6 pass.

eliare the-projecting stirrups which when fitted in the shell plating are used for .an-

choring the bracing bars and which, when flttedto the edge ofthefloorplates are used to take-a self 'ce'ntering open work steel reinforcement sheeting,*now well known as hyrib, .to which sheeting the bilge ceiling M (see Fig. 3) is: attached, since. ordinary wood centering could not be used for this purpose :as :it could not be removed, after the ceiling had been fitted.

a are the outer holes through which auxiliary longitudinals'e pass when these are fitted; e are-diagonal tie-bars which .are

at the ends of the floor sections. The main function of these tie bars is to stiflen the center keelson and the bilge keelson, by

bedded in thesemembers.

The bottom units are assembled, and the joint between the abutting flanges is made formin connected cross bracing when em- "as described, and. the bilge keelson and center keelson'are then'built in 'situ.

The arrangement of the side units, the bilge units and thefloor units in relation to the: sheer. strake,'side stringer, bilge keelson and'center keelson, are shown in Figs. 3, 4, and 5 in elevation, and in Figs. '8 and 9 in plan. In Figs. 4 and 8 the reinforcement bars are arranged longitudinally; in Figs. 5 and 9 they are arranged diagonally, and

' further details of the diagonal arrangement are given intheenlarged fragmentary view Fig. 6-.

The joints between the flanges of the units are made watertight as shown in the sec- 'tiOIlELl view Fig. 7, which is a horizontal section taken through the side plates.

In this case the flanges are keyed together :by formingrecesses a, which recesses are 'filled with bitumen or the like calking material 13, and this of course'may also be done in the case of the floor and bilge units.

The framefaces may be keyed in any suitable manner to prevent lateral displacement, and at intervals the flanges are made of additional depth toform web framing N, as shown in Figs3, 4, 5, 8 and 9.

The construction of-the sheer strake and the mode in which the deck units and side units are attached to the sheer strake is shown in Figs. 11 and 12; the deck beams D are cast as units and the deck 03 is cast in site, preferably in hy-rib concrete, d showing the hy-rib sheeting which is used in this connection. Additional holes ol are provided for additional longitudinals if :required, and the gunwale d is formed as shown integrally with the sheer strake, and is fitted with bulwark or open rails in any convenient manner.

Fig. 12 shows how the diagonal reinforces ment bars are anchored into the sheer strake.

Figs. 16 and 17 show the details of the hatch coamings P. The hatch coamings are cast in situ and united to the deck beamsv by anchoring the reinforcement bars d of the latter to the reinforcement bars p of the hatches. Protecting plates 10 of steel are let into the concrete where necessary. Slots p -ing pieces as to be incorporated in the concrete hull. Longitudinal members cast in situ run through the decks, usually on opposite sides of the hatchwayswhere they are made integral with the hatch coamings, and the longitudinal members join-and support the deck beans. Columns, also cast in situ are provided where necessary in the line of the longitudinal members, which latter, at the several decks, are arranged in'vertical alinement.

The provision of extra holes such as (11 6 and 7 through the sides of the units afford considerable latitude to the designer in the matter of additional strengthening members. Naked bars grouted into the sides of the units may be used and the behavior of these in'the unsupported parts between the sides would disclose any weakness by buckling and could then be stiffened by completing the reinforced concrete construction along the lines of weakness shown. This feature of the invention is of value in a new industry, wherein the absence of accumulated data, considerable excess of material is frequently employed in cases of doubt.

The system of construction according to the present invention however, would permit'of efficient repair, as any number of unit sections affected by the damage could with little difficulty, be removed and replaced by new units, matured prior to being placed,

as described keyed for the purpose of making the-joints, which are to be run. with waterproofed cement grout. It will be-noted that these joints occur nowhere in the'thin slabs forming the sides and bottom of the ship, but that they are of the full depth of the flanges a in the case of the sides and of 7 the depth of the floor plates 6 and f in the case of the bottom, thereby making possible Water-tight connections. 1

A careful examination of the stresses will show that there is no structural weakness due tothe .vertical joints between thefianges of the units as compared .for instance with continuous longitudinal shell plating ,it will be seen that if the whole steel section of the reinforced concrete shell were made con- "tinuousand equivalent in sectional area to the shell plating specified by Lloyds, the concrete section would be prohibitive; but it will be noted that it is'possible in accordance with the present invention and, by means of the holes provided in the frames to pass continuous longitudinal steel, from end to .end of the ship, having a cross sectional area at least equal to the maximum sectional area of slab reinforcement which would be continuous in the sides or bottom of any ship constructed in the usual monolithic manner of reinforced concrete.

. The side plating for the most part in the case of a steel ship is of comparatively little value so fan as the resistance of tensile stresses due to hogging and sagging are concerned, on account of its proximity to the neutral axis, and itschief function, apart from holding out the water or holding in the cargo, is that of the web of. a plate girder, resisting the shearing forces... And in the present system of design, means of resisting these stresses are provided as described.

It is to be understood that the example illustrated is given by way of example, and that the invention as claimed herein is capable, in respect of details of' construction, of considerable modification to meet the requirement of different types of ships and building conditions.

Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed, we declare that what we claim 1s:

1. In a reinforced concrete ship, in com- -bination; a series of pre-cast reinforced units each consisting of a plane part and two end flanged parts; reinforcing bars passing through the said flanged parts and projecting through the ends thereof and adapted with the flanges to form sections of one of the ships frame members; reinforcing bars 'irr'the plane portions proj ecting b'enected together end to end by jointsfmade between the faces of the; flanges and" being connected, together at their edges by the frame me'mbers'cast a, site, the reinforcing bars of the flanges being connected together in the members cast in situ and forming continuous framemembers runningiin the one direction connected at intervalsto the cast in situ frame members running in a direction at right angles; substantially as described. V

2. In a reinforced concrete ship, in combination a series of pre-cast reinforced units each consisting of a plane part and two end flanged parts; reinforcing bars passing through the said flanged parts and projecting through the ends thereof and adapted with the flanges to form sections of one of the ships frame members, reinforcing bars inthe plane aortions projecting beyond the edges thereof, consisting of reinforcing bars and concrete, cast in site, at right angles tothe frame members of which the flanges of the units form parts, and diagonal reinforced secondary frame members cast in site, the said pre-cast units being connected together end to end by joints made between the faces of the flanges and being connected together at their edges by the frame members cast in sir/a, the reinforcing bars of the flanges being connected together'in the members cast in situ and forming continuous frame members running in the. one direction connected at intervals to the cast in site frame members running in a direction at right angles, said diagonal reinforced secondary frame members passing diagonally through the frame members formed by the flanges and having their ends connected together in the frame members cast in site, substantially as described.

3. In a reinforced concrete'ship, in combination, a series of precast reinforced units each consisting of a shell part and two end flanged parts, reinforcing bars passing through the said'flanged parts and projecting through the ends thereof and adapted with the flanges to form sections of. the

transverse frames of the ship, reinforcing bars in the shell portion projecting beyond the edges thereof, and longitudinal frame members of the ship consisting of longitudinal reinforcing bars and vconcrete cast in situ, the said pre-cast units being con nected together end to end by. joints made between the faces of the flanges, the sets so connected together forming longitudinally disposed zones of pre-cast units, the edges frame members of the ship of adjacent zones being connectedtogether by a longitudinal member cast in I site, in

45.11 11 at reinforced concrete shi p, in comblnatlon, a serles of precast reinforced units eacli'consisting of a'shell partand two end flanged parts, reinforcing bars passing through.- the said flanged parts and projecting through the ends thereof, and adapted with the flanges to form sections of. the

transverse frames of the ship, reinforcing bars in the shell portion projecting beyond the edges thereof, longitudinal frame members of the ship cast in situ, diagonal reinforcing frame members cast in situ, the said pre-cast; units being connected together end I to end by joints made between the facesof the'flanges, the sets so connected together forming longitudinally disposed zones of precast units, the edges of adjacent zones being connected together by a longitudinal member cast in situ, in which the projecting reinforcements of the, shell parts are anchored and in which the reinforcing bars of the flange portions are connected together the said flange portions of the several zones being in line transversely so that they form suitably spaced continuous transverse members each jointed to the respective longitudinal members, said diagonal members being cast sit/u so as to be integral with the shell portion of the pre-cast units, and so as to pass obliquely through the flange portions of the said units and so that the ends of the reinforcing bars are connected together in the longitudinal members cast in site, substantially as described.

5. In a concrete ship, and in. combination 'with the elements of claim 1, a series of "metal stirrups cast in the flanges of the pre-cast units and projecting therefrom, and an inner lining or shell secured to the faces of the said flanges by the said stirrups, substantially as. described.

. 6. In a concrete ship as claimed in claim. 2, the pre-oast units provided with slots in the flanges thereof adapted after the units are assembled to take the reinforcing bars of the secondary diagonal members, substantially as described.

7 In a concrete ship as claimed in claim 1, diagonal bracing bars extending from the base of the one flange to the tip of the other flange of the pre-cast units, substantially as described.

'8. In a concrete Ship as claimed in claim the flanges of the pre-cast units and a calking material inserted in the spaces formed by the said recesses, substantially as described.

9. In a concrete ship as claimed in claim 3, deck beams, deck and hatch coamings cast integral in the longitudinal frame member forming the sheer strake, substantially as described. I V

10. In a concrete ship and in combination With the elements of claim 6, metal stirrups cast in and projecting from the shell parts of the units and adapted to connect the reinforcing bars of the secondary diagonal mem bersuto the said shell part, substantially as described. r j

11. In a concrete ship and in combination -With the elements of claim 3, constructing In Witness whereof We have set our hands in presence of Witnesses, v s t HARRY CHRITO HIE.

MORITZ KAHN. V v V Witnesses to signature of Harry Clement Ritchie: r

J. E. LLOYD BARNES, JOSEPH E. Hms'r. Witnesses to signature of Moritz Kahn:

MARGURITA JONES, JOSEPH E. HIRST. 

